Process of treating fibrous materials



UNITED STATES PATENT OFFICE.

PROCESS OF TREATING FIBRDUS MATERIALS.

No Drawing. Application filed January 27, 1917, Serial No. 145,028. Renewed Specification of Letters Patent.

Patented May 30, 1922.

To all whom it may concern: 7

Be it known that 1, DAVID E. DE LAPE, a citizen of the United States, residing in the city of Los Angeles, county of Los Angeles, State of California, have invented certain new and useful Improvements in Processes of Treating Fibrous Materials, of which the following is a specification.

This invention relates to improvements in process of treating fibrous materials and refers more particularly to a chemical or a combined mechanical and chemical process of decorticating fibre and also separating it from the pulp, glutens and coloring matter.

Among the salient objects of the invention are to provide a process in which the fibre of a plant is not only freed from the outer sheathing or bark and the pulp or glutinous matter and juices but in which this is accomplished in such a way as to avoid any injurious or disintegrant action on the fibre itself; to provide a process of the character last referred to in which the fibre is markedly strengthened and has imparted to it a maximum of pliability; to provide a process which converts the fibre into a finished product which is not only tough and pliable but has a silky and glossy lustre similar, for ex* ample, to that imparted by the well-known mercerizing process; to provide a process which is adapted for use either with green or with dried material and which in either case imparts to the treated fibre the above characteristics; to provide a process which so treats the material as to render it in excellent condition for either cordage or for textile making and is adaptable for use in connection with a Wide range of industries; to provide a process in which the treating solution acts very rapidly thus permitting the treating of a maximum quantity of inaterial in a minimum time; to provide a process which can be operated very economically and in which the chemical solution is not only inexpensive but in which the ingredients thereof are readily accessible in the market; to provide aprocess in Which starting with a plant stalk or leaf in its natural condition it is or may be successively rolled, brushed, scraped, combed and subjected to the required solution, dried, brushed, rinsed and bleached, or may be finished ready for textile or cordage purposes without mechanical aid, all as a substantially continuous process; to provide a process which is adapted for use with a wide variety of plants such as American flax, cotton stalks, hemp, palms, ute, the yuccas, thistles, nettles, ramie, rice straw, oat straw and nearly all of the fibrous materials that contain a bast or a longitudinal' fibrous system; to provide a system in which the precipitated and separated gluten pulp or uices after being removed from the fibrous material, for a valuable by-product for fertilizing, dyes, paper pulp or other purposes, and in general to provide an improved process of the character referred to. I am aware that heretofore many attempts have for various purposes and that for some purposes they have been commercially so handled as for example in the treatment of Central American sisal grass in the manufacture of twine and the like; also in the manufacture of manila rope and the like. Such processes are, however, practical only where the cheapest labor is to be had as the process requires a large amount of manual labor. The retting of fibre in Europe in the manufacture of linens is also a long and relatively expensive process. By my improved method the fibre is decorticated or retted and in a quick and economical manner and made into, as far as l am aware, a new product, which product, however, forms no part of the present application.

Describing now the principal steps in my progress. The plant leaf or stalk, 1f green, is first preferably rolled to force out of the plant as much of the juices, gluten and oils as possible, in order to lessen the work of the treating solution. These rollers are preferably cold as it is not desired tomake the plant too dry before treatment. A11 suitable pressure rolls may be used but it is to be understood that the fibre should not be crushed in such a way as to injure them.

March 8, .1922. Serial been made to decorticate fibres After the plants or stalks have been rolled,

above stated, it is then put in the treating solution. It remains in this solution in the cases which I have heretofore treated it, from fifteen minutes to two hours. The length of treatment, also the strength of the solution, depend upon the character of the material and upon the purpose for which it is to be used. The character of the solution will be hereinafter more particularly described. This dissolving treatment loosens the bark or sheathing from the fibre, discharges the coloring matter and loosens the pulp, gluten or flesh of the plant, classed together ness of natural dry and brittle fibers, and strengthens and toughens the fibre without disintegrating the same. It also imparts to the fibre a gloss or lustre as heretofore stated.

After the fibre has been removed from this solution it is passed through suitable wringing rolls separated from the solution which is saved. the gluten or pulp is also wrung out. -These rolls are preferably cold and dry. The material is then passed between revolving brushes to remove any adhering particles and to straighten the fibres. It is next rinsed in hot and cold water, or hot or cold water alone, to wash and clean it, which also helps to bleach it. It is to be understood that it is advisable or necessary to get out all the coloring matter or pulp. If desired, material may be added to the rinsing liquid to facilitate the" bleaching.

The material is next dried which completes the bleach. This may be done either by subjecting it to the action of the sun rays or by artificially drying.

The material is finally beaten, brushed and baled. The finished fibre is nearly pure cellulose, the leaf or stalk having been changed from its natural color of green, yellow, brown or the like, to a white or creamy white shade. It is lighter in weight than the original green material, is soft, silky and glossy, and is relatively much stronger than the original green fibre.

Describing now the character of the solution, 1t consists essentially of a vehicle, a detergent and a disintegrant. In the treatment of hemp straw, flax straw, phormium tenax, yucca plants and the like, the solut1on may consist of approximately 2,000 parts of liquid vehicle, two parts of a mild detergent, and one part of active re-agent,

and two ports of less active agent. More specifically, the solution might consist of 2048 parts of water, two parts of sal soda, one part caustic soda and two-parts of a saponifying compound consisting of a fatty material such as animal greases, horse tallow, palm oil, whale oil, fish oils and tallows, with a relatively large percentage of resin or the like. The detergent may conas albuminoids, reduces the brittle- The' coloring and part of,

sist of a compound comprising grease or tallow, oils such as palm oils, fish oils and the like, resin, caustic soda solution or a caustic potash solution, sodium carbonate and sodium silicate, the latter being-a softening or precipitating agent to soften the water. I have found that in certain cases the following solution is satisfactory:

180 parts of grease or tallow;

20 parts of crude palm oil;

40 to 80 parts of resin;

140 parts of caustic soda lye of 36 180 parts of water;

80 parts of sodium silicate;

20 parts of caustic soda lye of 36 B. d1- luted with 4 parts of common salt dissolved in 16 parts of water,

It is to be understood that the percentage of ingredients can be very greatly varied but it is advisable to get a large amount of resin and i'n"order to get the necessary silky and glossy effect, there should be some means of softening the water.

I have found that in certain cases 25 parts of caustic soda to 100 parts of fat is ample. The solution can be made by adding water to the caustic soda thus making a lye sOlution.

It is to be understood that as regards the main solution that it may be weaker in the caustic properties where the plants are more easily decorticated, also that a larger percentage of the detergent may be used where the plants are very .dry or of very hard material. \Vhere pressure is used the length of treatment should be less but the temperature of course will be higher. I have that the detergents may vary in their percentage of resln and also in the amount of caustic soda and sodium carbonate used; also paraffin wax, borax and oils of a petroleum base may be used in the solutions as conditions may direct. Where a yery high degree of softness of the fibres is desired, the detergents may be used containing no caustic soda if an equivalent such as caustlc potash is used with the sodium carbonate. It may also be stated that all waste matter formed in the process of saponifying the fats and Y resins may be separated from the same by addition to the compound of common salt. The detergent or cleaning properties of these compounds is due partly to their great penetrating powers in comparison w1th other liquids together with the reactive action of the freed acids in dissolving and carrying away the detritus matter. The use of the caustic soda or its equivalent in the solution acts to break down and dissolve the tissues and release the fibers from cellular matter.

A fatty material from anlmal fat is particularly good as it contains glycerides of alcoholic nature, also stearic, palmltic, oleic, and other acids.

found This solution is heated preferably practically to its boiling point. It is also desirable that the material be heated under pressure as this tends to cause the solution to come into more intimate contact with each particle of the material being treated.

It is understood that the proportion may be varied somewhat from the proportions above stated, although I have found that a relatively small percentage of the alkaline and a relatively small percentage of the detergent material can be used with a large amount of Water. But care should be taken that if alkaline (caustic soda or the like) is used in a free state, that it is not combined in a saponifying mixture with the fats, that such alkaline be of so small a percentage of the solution that it will not injure the fibre. A ire-agent which is the equivalent may be substituted for the canstic soda and in certain cases the sal soda or sodium carbonate might be dispensed with. The detergent acts as stated as a detergent and I have found that the addition of resin is very desirable. it is to be understood that the solution must not be of such a character as to injure the fibre. Furthermore this particular solution gives strength, p-liability and gloss to the fibre which I have been unable to obtain with any of the processes heretofore used for treating fibrous material for similar purposes. The waste material which 15 precipitated from the fibre can be collected and serves as an excellent fertilizer, particularly inasmuch as both the pulp and the solution contain a certain percentage of potash. The short or tow fibres which are scraped ofifrom the long fibres make excellent pulp material for paper making and the like and I have discovered that these short fibres made by old retting process, While not suitable without reduction by very strong caustic solutions for this purpose, are, after being subjected to the action of my process, very satisfactory for this purpose after being so treated.

I claim as my invention:

1. A process for treating fibrous material consisting in passing the material between rollers, scraping, brushing, and combing materials subjecting the material to the action of an aqueous solution, consisting of not less than 500 parts of a fluid vehicle such as Water, not more than 5 parts of an active reagent or saponifying compound such as caustic soda and not more than 10 parts of a compound containing an oily substance and a substantial percentage of resin, and then pressing material after being removed from the aqueous solution, brushing the same and bleaching.

2. A process for treating fibrous material consisting in passing the material between rollers, scraping, brushing and combing the material, subjecting the material to the action of an aqueous solution consisting of not less than 500 parts of water, not less than 5 parts of caustic soda and not more than 10 parts of a saponifiable compound, the latter consisting of a major percentage of oily substance and a minor percentage of resin.

DAVID E. DE LAPE. l/Vitnesses:

F. L. BELKNAP, M. E. MACK. 

